For a variety of traffic categories, for example heavy loads, hazardous cargo, or heavy transports, certain roads and areas are, for various reasons (e.g. environmental reasons) closed to through traffic. These closures can be valid for a limited time, for example only for certain days of the week and/or for certain hours of the day. Corresponding traffic signs are provided for in German road and traffic legislation. At present, checks that such prohibitions are being observed are made in particular by laborious traffic inspections.
On the other hand, there exist proposals in conjunction with the charging of fees for the use of roads subject to fee, for example from European Published Patent Application No. 0 741 373, according to which stations are provided, at least upon entry into and/or exit from the area subject to fee, which recognize the passage of a vehicle and with which a unit installed in the vehicle communicates in order to calculate the fee amount.